Lubricating composition



2,349,224 LUBRICATING COMPOSITION Edward'A. Nill, Detroit, Mich, asslgnor to The H. A. Montgomery Company, Detroit, Mich, a corporation of Michigan No Drawing.

The present invention relates to an improved lubricating composition, and particularly a lubricating composition suitable for internal combustion engines.

It is an object of the present invention to provide a lubricating composition for internal combustion engines which will have long life and which will greatly decrease the wear of the working parts.

Another object of the present invention is to provide a lubricating composition which when added to commercial lubricating oils improves their pressure properties, prevents formation of sludge in the oil, and prolongs the effective life both of the oil in the composition and of the en ine.

A further object of the present invention is to provide a lubricating composition which will greatly decrease the wear of the worlrlng parts in the engine, increase the life of the lubricating oil, and greatly decrease the accumulation of carbon in the engine.

These and other objects which will be apparent from the following detailed description of the invention are accomplished by preparing a composition comprising a mineral lubricating oil, a metal soap of a fatty acid, one or more suitable higher alcohols, and sulphur.

Sulphur, halogenatedv organic compounds, soaps, etc. have heretofore been used as additive agents for lubricating oils in the preparation of greases having extreme pressure properties, but I have found that the combination of relatively small amounts of a suitable soap, sulphur and one or more higher alcohols in mineral oil yields a lubricating composition desirable for internal combustion engines and has vastly superior properties to one having much greater quantities of any single addition agent.

The sulphur, which cooperates with the higher alcohols and with the soap to increase the pressure properties of the composition, is preferably in the uncombined but dissolved state, being pres- Applloation November 22, 1940, Serial No. 366,695

cut in the oil in the form of solution rather than as a part of an organic compound. Inferior results are obtainid when the sulphuris either chemically combined with the oil, as when it is heated at relatively high temperatures in contact therewith, or when it is combined with oleflns, lard oil, or incorporated as a sulphur compound such as sulfides, mercaptans, etc. which may yield some free sulphur in use. Sulphur in its natural forms is substantially insoluble in mineral oil, butin my prior Patent No. 2,159,908 I have disclosed a method of preparing sulphur in such a form that it is soluble in mineral oil at low temperature to the extent of about 1%,% or

so. Such sulphur is preferred, and in combi-- nation with suitable alcohols and soaps imparts superior wear-resistant and pressure properties to the composition.

Although some of the benefits of the present invention may be obtained with the various metal soaps of a rosin or a fatty acid, the heavy metal soaps, such as zinc soaps and lead soaps, usua y yield superior results, and much improved resu ts are obtained with soaps of the fatty acids of the oleic or unsaturated series, particularly soaps of acids found in sperm oil.

Zinc soaps, particularly zinc soaps of sperm oil acids, have exceptional properties in preventing the accumulation of carbon in the engine and in cooperating with sulphur and the higher alcohols in improving extreme pressure resistance of the composition and in affording superior lubricating qualities to the oil.

During the operation of engines lubricated with the composition of the. present invention, sufli-' cient of the zinc compound appears to be projected into the combustion chamber to cause the interior surfaces, particularly the spark plugs or the ignition, to be coated. The zinc in the composition may be transformed into a zinc salt, such as the sulfide or carbonate, which salt appears to form a dust having relatively little adhesion to the surface of the metal and may be readily blown therefrom, carrying with it any carbon particles and thus prevents accumulation of carbon.

The alcohols inhibit sludge formation and in combination with the fatty acids or derivatives thereof, particularly the above soaps, further improve the pressure properties of the lubricating composition.

In order to obtain the more substantial benefits of the composition, the alcohols should con,- tain an aliphatic chain of at least ten carbon atoms. Preferably, the alcohols should be of the aliphatic series having at least twelve or fifteen carbon atoms, or more.

Much superior results are obtained when these long chain alcohols are of the unsaturatedv or ethylene series. The alcohol should preferably be present in the composition in-the amount of about .1 to about 3%, although as little as .05% yields noticeable results, and as much as 11% or .5% is sometimes desirable. A very desirable source of the higher alcohols and also of the soap forming acids for combination with the metal is sperm oil.

Lewkowitsch, in volume II of "Chemical Technology and Analysis of Oils, Fats and Waxes, states that sperm oil, particularly the winter refined sperm oil which has been found quite desirable, contains about 60% to 65% of fatty acids, primarily of the oleic series, about 14% of which are solids and about 86% of which are liquids, and the balance of about 35% to 40% being mostly alcohols.

The alcohols belong for the most part to the ethylene series and although they have not been separately identified, they are believed to include the alcohols CisHsiOH, C18H350H, and CzoHasOH in major proportion; cetyl alcohol (CmHasOH) and palmitic acid have also been identified in the sperm oil.

Talloil is also a desirable source for soap forming acids and alcohols. Talloil, either crude or refined, is the byproduct obtained from the wood of coniferous trees during the process of conversion of the wood fibers intocellulose by the sulfate or Swedish process for pulp. making. It is a mixture of 38% to 50% rosin acids, 40% to 60% fatty acids, and 5% to of the higher alcohols, such as lauryl alcohol, stearyl alcohol, oleyl alcohol, etc. a

The soaps and alcohols suitable for the preparation of lubricating compositions can be conveniently obtained from sperm oil or talloil by saponifying the oil with a strong alkali, such as sodium forming sodium soap; and if a heavy metal soap, such as zinc soap is desired, this may be obtained by precipitating the zinc soap with a soluble zinc salt as zinc chloride.

The quantity of sulphur in the lubricating composition should preferably be about .15% or between .05% and about .25% of the composition. While the quantity of sulphur may be increased to 1% or 2%, its greatest efiectiveness appears to be in small quantities up to .25% or even .5%. If sulphur in the form of a sulphur compound is used, a much larger amount should be present in order to obtain the same effectiveness. Thus, it has been found that it usually requires about or so of a highly sulphurized lard oil in the composition to obtain the same film strength as is obtained with 1% of soluble sulphur prepared as set'forth in my above mentioned prior patent.

Soap is preferably present in the amounts of .3% and .5% in the lubricating composition, although substantial benefit is obtained with as little as .l% of a heavy metal soap, such as zinc soap.

To facilitate the marketing of the composition, it is often desirable that the active ingredients be prepared-in a more concentrated form for addition to the lubricating oils. Such a composition is illustrated by the following example, wherein the parts are by weight.

Example The following composition was prepared for addition to motor oils in the ratio of about one quart of the composition to about six or seven quarts of a motor oil suitable for internal combustion engine use.

In the above example, th preferred quantity of alcohols is about 1 part, the metal soap about 2 parts, and of free sulphur about .75 part.

The thinner may or may not be present in the composition, but it is desirable when the viscosity of the oil isincreased to a large extent by the soap used. The sulphur is dissolved without any appreciable heating in the mineral oil and in the solvent.

Instead of zinc soap, other metallic soaps such as those of lead, mercury, aluminum, calcium, barium, tin, chromium, iron and copper may be used.

The additive composition may be made up in various concentrations, but the solid constituents thereof should be present in such proportion that when added to the lubricating oil for an internal combustion engine there will be about .1% to .2% sulphur in solution, about .1% to 4% metallic soap, and about .05% to .2% of the -high alcohols.

The composition disclosed herein is advantageous for use with petroleum lubricating oils, and particularly those for the lubrication of internal combustion engines. The composition appears to have the effect of giving better lubrication, prolonging the life of the lubricating oil itself, and accomplishing these results with a relatively low viscosity petroleum oil. This is of material advantage in that internal combustion engines are being lubricated with petroleum oils of lower viscosity than formerly, and the use of applicant's composition makes it possible to use still lower viscosity oils and yet obtain excellent or improved lubricating qualities.

In the operation of internal combustion engines with the above composition, bearings are substantially discolored or blackened, and the friction of the engine is reduced to a marked degree so that there is a marked reduction in fuel consumption.

The use of the additive composition disclosed herein with petroleum oil for the lubrication of internal combustion engines tends to prevent formation of sludge in the oil and prolongs the effective life of the lubricating oil thereof. After operating an engine for a considerable period of time with the lubricating composition of the present invention, the walls of the combustion chamber become coated with a loosely adherent gray deposit, which upon analysis appears to be a mixture of zinc salts, such as the sulfide and carbonate, and some carbon. This composition seems to be gradually displaced and ejected in the operation of the engine, for it does not accumulate in substantial quantity and the accumulation of hard, thick deposits of carbon does not occur.

It has also been found that the active constituents of applicant's composition, metallic soap, the sulphur and the alcohols, may be added to the motor fuel and benefits of the invention obtained. The effects of the composition when used in motor oil or in the motor fuel may be noted for a considerable period of time after the motor oil has been removed and after the fuel has been replaced by a fuel which. does not contain the composition. It appears that the working parts have been coated desirable non-frictional properties.

Furthermore, it is to -'-be understood that the particular form of product described, and the particular procedure set forth, are presented for purposes of explanation, and that various modications of said product and procedure can be with a film having exceedingly made without departing from my invention as defined in the appended claims.

What I claim is:

i. A readily fiowable, oily lubricating composition for internal combustion engines, comprising mineral oil, to of sulphur dissolved in mineral oil. a heavy metal soap in the amount of .l% to 5%, and an alcohol having at least twelve carbon atoms in a chain in the amount of .05% to 3%.

2. A readily fiowable, oily lubricating composition for internal combustion engines, comprising mineral oil, .l% to 5% of sulphur dissolved in mineral oil, a heavy metal soap in the amount of .l% to 5%, and an alcohol of the ethylene series having at least twelve carbon atoms in a chain in the amount of .05% to 3%.

3. A readily fiowable, oily lubricating composition for internal combustion engines, comprising a lubricating oil, an unsaturated alcohol of the ethylene series having at least twelve carbon atoms in an amount of about .05% to about 5%, a small amount of sulphur dissolved in the mineral oil. and a small amount .of a zinc soap of sperm oil acids, the amounts of said additions being suificient to decrease the tendency for sludge formation in said lubricating oil and to reduce the coefficient or"- friction of a surface lubricated with said composition below that of "the same surface lubricated with said mineral oil without the sulphur, soap and alcohol.

4. A readily fiowable, oily lubricating composition for internal combustion engines, compris ing a lubricating oil, 05% to 5% of sulphur dissolved therein, a small amount of a heavy metal soap of sperm oil acids, and a small amount of a higher aliphatic alcohol having at least ten carbon atoms, the amounts of said additions being sufficient to decrease the tendency for sludge formation in said lubricating oil and to reduce the coefficient of friction of a. surface lubricated with said composition below that of the same surface lubricated with said mineral oil without the additions.

5. A composition for addition to readily flowable, oily lubricating oils of motor vehicles comprising mineral oil, 14% to 1.25% sulphur dissolved in said mineral oil, .8% to 4% of a heavy metal soap, and .05% to 2% of a higher alcohol containing at least ten carbon atoms in a chain.

6. A readily fiowable, oily lubricating composition for internal combustion engines, comprising a mineral lubricating oil between '10 and 350 sec. Saybolt at 100 E an oil soluble sulphur in the amount of 135% to a zinc soap in the amount of .l% to 5%, and an unsaturated aliphatic alcohol having at least ten carbon atoms in the amount of .05% to 3%.

7. A homogeneous, stable, readily flowable lubricating composition for internal combustion engines, comprising mineral oil, .05% to .5% 'of a higher alcohol containing at least ten carbon atoms in a chain, sulphur in said oil in an amount of .05% to 5%, and a metal soap of higher fatty acids in an amount of about .1% to .5% of the composition.

8. A readily flowable lubricating composition for internal combustion'engines, comprising mineral oil having dissolved therein .05% to .5% of sulphur, .05% to .5% of a higher alcohol containing at least ten carbon atoms, and from about .l% to about .5% of a metal soap of higher unsaturated fatty acids.

9. A readily fiowabie, oily lubricating composition for internal combustion engines, comprising a mineral lubricating oil of between '70 and 350 sec. Saybolt at F., and dissolved in said mineral oil relatively small amounts each of sulphur, a metal soap of a higher fatty acid, and a higher alcohol containing at least ten carbon atoms in an aliphatic chain, whereby the formation of sludge in the mineral oil is inhibited and the friction between surfaces lubricated with the composition is reduced therewith below that between the same surfaces lubricated with the mineral oil without the additions.

10. A readily flowable, oily lubricating compo sition for internal combustion engines, consisting essentially of a mineral oil containing appreciable amounts of up to .5% sulphur, relatively small amounts up to about 5% of a higher alcohol containing at least ten carbon atoms and relatively small amounts up to about 5% of a heavy metal soap of higher unsaturated fatty acids, the additions being present in suflicient amounts to decrease the friction of surfaces lubricated with said composition below that of the same surfaces lubricated with said mineral oil without said additions.

11. A readily fiowable oily composition comprising lubricating oil, about .05% to about 2% of an oil-soluble sulphur, about .1% to about .5% of a metal soap of a higher fatty acid, and an amount of about .05% to about .5% of an alcohol containing at least ten carbon atoms in an aliphatic chain.

12. A homogeneous, stable, composition. comprising mineral oil, .05% to about .5% of sulphur in said oil, higher talloil alcohols and metal soapsof talloil fatty acids, said alcohols being present in amounts between about .05% to about 5% and said metal soaps being present in an amount of about .1% to about .5% of the composition.

readily flowable EDWARD A. HILL. 

